Field
This disclosure relates generally to wireless communication, and more specifically, to carrier frequency offset (CFO) estimation for wireless communication.
Related Art
Deployment of Internet of Things (IoT) relies on networks of low-cost wireless devices that work reliably in the presence of interference. Internet of Things standards includes, for example, IEEE standard 802.15.4 (used by Zigbee and Thread standards). These standards use pseudo noise (PN) coding sequences over O-QPSK (offset quadrature phase shift keying. One disadvantage of O-QPSK is sensitivity to carrier frequency offset (CFO) between the transmitter and receiver. Poor CFO estimation results in poor demodulator performance in the presence of crystal frequency mismatches between various nodes in an IoT network. Various frequency offset estimation techniques are used to correct for CFO in the receiver. However, the various techniques can be complex and expensive in terms of hardware and memory usage.
Therefore, a need exists for a low-cost technique for frequency offset estimation that also provides good demodulator performance.